I think the problem is that most of those games had literally 15 second clips shown. Some got 30, but none got full "trailers." The music was overlapping between one and the next, they were run so closely together. So it was hard to get "hyped" about any of them. And yeah, those games all look good, but very little "new" was shown PS2 besides Rogue Galaxy. Devil Summoner PS2 looks good tho - basically SMT3, but SMT3 looks awesome. Main guy had a black outfit and a sword.
I guess it's less that the PS2 announcements were "weak" and more than Sony's PS2 showing at this conference was "weak." They have good software, they just chose to ignore it for the most part.